Web winding mechanism



June 17, 1969 H. R. w. MARSH ETAL 3,450,364

WEB WINDING MECHANISM Filed Dec. 19, 1967 Sheet of 3 'AfTnRn/EX: r

June 17, 1969 H. R. w. MARSH ETAL 3,450,364

WEB WINDING MECHANISM Filed Dec. 19, 1967 Sheet 3 of s IWENTORJ ///7/ [fr/Z1;

Julile 1969 H. R. w. MARSH ETAL 3,450,364

WEB WINDING MECHAN I SM Filed Dec. 19, 1967 v Sheet 3 of s United States Patent U.S. Cl. 242-66 9 Claims ABSTRACT OF THE DISCLOSURE A mechanism for winding 2. web (e.g. of paper) into a roll has two drums by which the roll being formed is both supported and driven. Both drums are connected to a drive motor, the connection to one drum being through a differential gear provided with a brake for its third rotary member, the brake being controlled in accordance with the size of the roll being wound so that the speed of the one drum varies as the roll size changes.

This invention relates to mechanism for winding webs of paper or like materials into rolls. In performing such winding, it is important to control the web tension as not only may excessive tension cause web breakage, or insufficient tension cause a sloppy roll to be produced, but the application of tension as the web enters the roll being formed causes the web to be stressed within the finished roll and such stressing, if excessive, may make it difficult to handle the finished roll without damage.

It has been found that the tension required in a paper web before winding, e.g. while it is being slit longitudinally, is often different from that which is desirable as the web enters the roll being formed; the latter tension may also with advantage be varied as the roll grows, and therefore it has become a recognized practice to provide for separate control of the web tension as it enters the roll. A convenient way of achieving this comprises passing the web through the nips formed by two drive drums each pressing against the roll being formed, the speed of the second drum being variable relative to that of the first drum. As the roll being formed need not be driven directly, it may rest on the two drive drums; it will be realised that the centre of the roll will rise as the roll grows larger.

It is an object of the present invention to provide a mechanism for winding a web of paper or like material into a roll, with improved means for controlling the tension of the web as it enters the roll.

According to the invention, there is provided a mechanism for winding a web of paper or like material into a roll, comprising a pair of drive drums mounted in spaced parallel horizontal positions so as to permit a roll being formed to be both supported and driven by said drum, a motor or the like, and transmission means providing drive connections from said motor or the like to both said drums, the drive connection to one drum being a positive drive connection and the drive connection to the other drum including a differential gear assembly (as hereinafter defined), said assembly having a first member connected to the motor or the like, a second member connected to said other drum, and a third member associated with a brake, including means for controlling said brake in accordance with the size of the roll of paper or the like being wound.

By the term differential gear assembly we mean any form of gearing having three members which may serve as input or output members of the assembly and are so interconnected that the motion of any one of the three members is determined by the motion of both the other two members; if any one of the three members is left free the assembly provides no drive connection between the other two members but if the one member is held stationary, such a drive connection is established. Thus the scope of the said term thus comprehends both differential gears and epicyclic gears.

In the case when one member of the differential gear assembly is held stationary, it then acts as a reaction member in the drive connection provided between the other two members. By applying to the said one member a braking effort insufficient to hold it stationary, some movement of the one member is permitted and there is established between the other two members a drive connection with an effective ratio which is dependent upon the braking effort applied. The relationship between the size of the roll and the speed of the said other drum, as well as the relationship between the braking effort and the effective ratio of the drive connection through the differential gear assembly must both be allowed for in the control means. As a preferred arrangement, We employ a pneumatically-operated brake: the size of the roll is sensed by causing a spindle on which the roll is formed, and which rises as the roll grows, to move an endless chain passing round several sprockets, one of which is on a shaft also carrying a cam arranged to operate an air valve for control of the brake. With this arrangement, it will be appreciated that the form of the cam is so determined as to provide the desired relationship between the roll size and the drive speed of the said other drum.

In order that the invention may be well understood, a preferred embodiment thereof will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a diagrammatic perspective view of a mechanism embodying the invention,

FIGURE 2 is a diagrammatic sectional view of a differential gear assembly included in the mechanism of FIGURE 1, and

FIGURE 3 is an outside end view of tha assembly of FIGURE 2, showing also a brake associated therewith.

Referring first to FIGURE 1, a mechanism is shown for winding a roll of paper 1 on a spindle 2; the roll is supported on and driven by two drums 3, 4. Abutment members 5' 6 have vertical guide faces 5a, 6a respectively against which protruding end portions 2a, 2b of the spindle 2 rest. With the directions of movement of the drums and roll indicated by arrows, it will be seen that the members 5, 6 prevent horizontal movement of the spindle 2 while allowing it free vertical movement.

It will be seen that the end portions 2a, 2b of spindle 2 do not engage the guide faces 5a, 6a directly, but through the intermediacy of blocks 7, 7a journalled on said end portions 2b, 2a respectively. A chain 8 secured to the block 7 forms an endless loop around four sprockets carried by horizontal shafts which are supported in the member 6; of these sprockets and their shafts a sprocket 9 is adjacent to the upper end of the guide face 6a, and a sprocket 10 is horizontally spaced from the sprocket 9, adjacent to the top rear corner of the member 6 (considering the guide face 6a as the front face of said member). The other two sprockets are in corresponding positions at a lower level; these two sprockets and the sprocket 9 are all free on their shafts, but the sprocket 10 is secured to its shaft so as to drive a cam 11 to which further reference will later be made. The block 7a also has a chain secured to it, the arrangement of this chain over sprockets being similar to the arrangement of the chain 8 but not having an associated cam corresponding to cam 11.

Returning to the drums 3, 4, these are carried on shafts 12, 13 respectively, said shafts in turn being supported in bearings 14 in conventional manner. Shaft 12 also carries a pulley through which drive is received, via multiple belts 16, from an electric motor 17.

The shaft 13 is also the output shaft of a differential gearing assembly 18 which has an input shaft 19 coaxial with the shaft 13. Pulleys 20, 21 secured in aligned positions on shafts 12, 19 respectively carry a belt 22 through which drive is transmitted to the shaft 19.

Now turning to FIGURE 2, the differential gear assembly 18 comprises a cylindrical casing 23 coaxial with shafts 13, 19 and carrying planet shafts 24 parallel to and regularly spaced around the common axis of shafts 13, 19. Each shaft 24 has secured to it two planet pinions 25, 26. All the planet pinions 25 are disposed so as to mesh with a sun gear 27 secured to the input shaft 19 while all the planet pinions 26 are arranged to mesh with a sun gear 28 secured to the output shaft 13. The casing 23 carries externally a chain sprocket 29 (FIGURE 3) connected by a chain 30 to a further sprocket 31 secured to a brake drum 32. Around the drum 32 are symmetrically arranged a pair of brake shoes 33 provided with a common pneumatic actuator 34, connected by a pipe 35 and a control valve 36 (FIGURE 1) to any suitable source of compressed air (not shown). The valve 36 is arranged to be operated progressively by the cam 11, and accordingly the supply of compressed air to the actuator 34 (and hence the braking effort applied by the shoes 33 to the drum for transmission by chain 30 to the casing 23) is con-' trolled according to the size of the roll 1. The drum 32 is desirably internally water-cooled.

The operation of the differential gear assembly can readily be understood by reference to FIGURE 2. Whenever its input shaft 19 is driven, the sun wheel 27 rotates and causes the planet pinions 25 to rotate, hence the planet shafts 24 and planet pinions 26 also rotate. If the casing 23 is held stationary, then the rotation of the pinions 26 drives the second sun wheel 28 and hence the shaft 13; however, if the casing 23 is free to rotate, while there is some resistance to rotation of the shaft 13, then 1 it will be found that the planet pinions 26 do not drive the sun wheel 28, but roll round it, causing the casing 23 to rotate idly.

Between these two extreme conditions, we have an infinite range of intermediate conditions, in which some retarding torque is applied to the casing 23 by applying the brake shoes 33 to the drum 32. In any such intermediate condition, the casing 23 cannot rotate with complete freedom and some motion is transmitted to the shaft 13; the larger said retarding torque, the greater the proportion of the drive from the input shaft 19 which is communicated to the shaft 13. The speed and torque received by the shaft 13 in any such intermediate condition can be calculated by normal techniques.

The retarding torque applied to the drum 32 therefore governs the drive imparted to the shaft 13, and is itself controlled by the valve 36. Said valve 36 is operated by the cam 11, and the rotational position of said cam at any instant is determined by the height of the spindle 2, which in turn indicates the size of roll 1. It will therefore be appreciated that the cam 11 must not complete more than one revolution when the spindle 2 and block 7 traverse their full range of movement, and therefore the cam 11 is not secured to the shaft of sprocket 10 but is carried on a separate shaft and is driven by the shaft of sprocket 10 via reduction gearing 37. If desired, however, the reduction gearing 37 may be omitted and the cam 11 secured to the shaft of sprocket 10, provided that the sprocket 10 is sufficiently large to rotate not more than one revolution when spindle 2 and block 7 traverse their full range of movement.

' It will be seen that the mechanism described provides a convenient means of driving the two drums 3, 4 with automatic variation of the speed of the drum 4 as the roll 1 grows. While the arrangement described is at present considered preferable, various changes or modifications may be made without departure from the scope of the invention. For example, in place of the block 7, chain 8 and associated parts, the cam- 11 may be operated by a follower member riding on top of the roll 1, and/or in place of pneumatic brake operation, we may provide hydraulic, electric, or mechanical braking. In place of the brake drum 32, we may provide a brake disc secured directly to the casing 23, with for example opposed'brake pads in a caliper-type mounting.

What we claim as our invention and desire to secure by Letters Patent is:

1. A mechanism for winding a web of material such as paper into a roll, comprising a pair of drive drums mounted in spaced parallel horizontal position so as to permit a roll being formed to be both supported and driven by said drums, drive motor means, a positive drive.

connection from said motor means to one of said drums, a drive connection from said motor means to the other of said drums comprising a differential gear assembly, an input shaft connecting the assembly to the motor means and an output shaft connecting the assembly to the other of said drums, said assembly comprising a first member connected to the input shaft, a second member connected to the output shaft and a third member drivingly coupled to both said first and second members, a brake operative on said third member, and control means responsive to increases in the size of the roll being formed for regulating said brake.

2. A mechanism as claimed in claim 1, in which the brake is pneumatically-operated.

3. A mechanism as claimed in claim 1, including a spindle on which the roll is formed and means linking said spindle to the control means. I

4. A mechanism as claimed in claim 3, in which said means linking said spindle to the control means comprises an endless chain secured to said spindle and passing around a plurality of sprockets, one of said sprockets being operatively connected to the control means.

5. A mechanism as claimed in claim 4, including a shaft carrying said one sprocket and a cam arranged to be operated by said shaft to operate said control means.

6. A mechanism as claimed in claim 5 wherein said brake is pneumatically operated and said mechanism further comprises an air valve for controlling said brake, said air valve being arranged to be operated by said cam.

7. A mechanism as claimed in claim '5, including reduction gearing connecting said shaft to said cam.

8. A mechanism as claimed in claim 1, in which the brake includes a brake'drum spaced from said differential gear assembly and a sprocket secured to said brake drum, said differential gear assembly comprises a further sprocket secured to the third member, and a chain connects said sprocket to said further sprocket.

9. A mechanism as claimed in claim 1, in which said input and output shafts are coaxial, the first and second members of the dilferential gear assembly comprise sun gears mounted on said input and output shafts respectively and the third member comprises a casing enclosing said sun gears and carrying planet shafts on which planet pinions meshing with said sun gears are mounted.

References Cited UNITED STATES PATENTS WILLIAM S. BURDEN, Primary Examiner. 

